[Bug bootstrap/46856] [4.6 regression] internal compiler error in final_scan_insn breaks m68k-linux bootstrap

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46856

--- Comment #5 from Mikael Pettersson <mikpe at it dot uu.se> 2011-01-18 
08:29:42 UTC ---
If I hack reload_combine_recognize_const_pattern to bail out early if HAVE_cc0,
then the test case doesn't ICE a cross to m68k-linux, and native bootstrap on
m68k-linux also succeeds (--enable-languages=c,c++; testsuite currently
running).

I'm not suggesting this is the proper fix, but at least it identifies roughly
were the problem lies.

--- gcc-4.6-20110115/gcc/postreload.c.~1~       2010-12-21 15:51:42.000000000
+0100
+++ gcc-4.6-20110115/gcc/postreload.c   2011-01-16 12:29:44.000000000 +0100
@@ -944,6 +944,11 @@ reload_combine_recognize_const_pattern (
   int add_moved_after_ruid = 0;
   int clobbered_regno = -1;

+#ifdef HAVE_cc0
+  /* Unbreak m68k, see PR bootstrap/46856. */
+  return false;
+#endif
+
   set = single_set (insn);
   if (set == NULL_RTX)
     return false;